A recent significant advancement in the field of generating low temperature refrigeration is the pulse tube and other cryocooler systems wherein pulse energy is converted to refrigeration using an oscillating gas. Such systems can generate refrigeration to very low levels sufficient, for example, to liquefy helium.
One problem with conventional cryocooler systems is contamination of the pulsing gas by leakage or offgassing. The contaminants reduce the efficiency of the cryocooler by freezing out at the cold temperatures characteristic of the cold portion or cold end of the cryocooler.
Accordingly it is an object of this invention to provide a method for operating a cryocooler system which reduces the contamination potential and provides for more efficient operation.